package com.changgou.search.service.impl;

import com.alibaba.fastjson.JSON;
import com.changgou.search.pojo.SkuInfo;
import com.changgou.search.service.SearchService;
import org.apache.commons.lang.StringUtils;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.index.query.BoolQueryBuilder;
import org.elasticsearch.index.query.Operator;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.search.SearchHit;
import org.elasticsearch.search.SearchHits;
import org.elasticsearch.search.aggregations.AggregationBuilders;
import org.elasticsearch.search.aggregations.bucket.terms.StringTerms;
import org.elasticsearch.search.fetch.subphase.highlight.HighlightBuilder;
import org.elasticsearch.search.fetch.subphase.highlight.HighlightField;
import org.elasticsearch.search.sort.SortBuilders;
import org.elasticsearch.search.sort.SortOrder;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.PageRequest;
import org.springframework.data.domain.Pageable;
import org.springframework.data.elasticsearch.core.ElasticsearchTemplate;
import org.springframework.data.elasticsearch.core.SearchResultMapper;
import org.springframework.data.elasticsearch.core.aggregation.AggregatedPage;
import org.springframework.data.elasticsearch.core.aggregation.impl.AggregatedPageImpl;
import org.springframework.data.elasticsearch.core.query.NativeSearchQueryBuilder;
import org.springframework.stereotype.Service;

import java.util.*;
import java.util.stream.Collectors;
import java.util.stream.Stream;

@Service
public class SearchServiceImpl implements SearchService {

    @Autowired
    private ElasticsearchTemplate elasticsearchTemplate;

    /**
     * 根据关键字 进行 查询
     * @param searchMap 参数查询
     * @return
     */
    @Override
    public Map search(Map<String, String> searchMap) {

        //构建返回结果对象
        Map<String,Object> resultMap = new HashMap<>();

        //构建查询
        if (searchMap != null){
            //构建条件封装对象
            NativeSearchQueryBuilder nativeSearchQueryBuilder = new NativeSearchQueryBuilder();
            BoolQueryBuilder boolQuery = QueryBuilders.boolQuery();
            //构建关键字查询
            if (StringUtils.isNotEmpty(searchMap.get("keywords"))){
                boolQuery.must(QueryBuilders.matchQuery("name",searchMap.get("keywords")).operator(Operator.AND));
            }

            //根据品牌 进行查询  进行 boolQuery 的连接查询
            if (StringUtils.isNotEmpty(searchMap.get("brand"))){
                boolQuery.filter(QueryBuilders.termQuery("brandName",searchMap.get("brand")));
            }

            //按照规格进行过滤查询
            for (String key : searchMap.keySet()) {
                if (key.startsWith("spec_")){
                    //进行数据的处理
                    String value = searchMap.get(key).replace("%2B","+");
                    //进行查询
                    boolQuery.filter(QueryBuilders.termQuery("specMap."+ key.substring(5) + ".keyword",value));
                }
            }

            //按照价格区间进行过滤查询
            if (StringUtils.isNotEmpty(searchMap.get("price"))){
                String[] prices = searchMap.get("price").split("-");
                if (prices.length == 2){
                    boolQuery.filter(QueryBuilders.rangeQuery("price").lte(prices[1]));
                }
                boolQuery.filter(QueryBuilders.rangeQuery("price").gte(prices[0]));
            }


            nativeSearchQueryBuilder.withQuery(boolQuery);

            //根据查询结果，进行品牌（聚合）分组  品牌聚合(分组)查询
            /**
             * AggregationBuilders.terms(skuBrand).field("brandName")
             * skuBrand：指 查询后的列名，叫什么
             * field("brandName")：指根据哪一个域 进行分组聚合查询
             */
            String skuBrand = "skuBrand";
            nativeSearchQueryBuilder.addAggregation(AggregationBuilders.terms(skuBrand).field("brandName"));

            //进行 规格信息的分组（聚合）查询
            String skuSpec = "skuSpec";
            nativeSearchQueryBuilder.addAggregation(AggregationBuilders.terms(skuSpec).field("spec.keyword"));

            //对查询的结果进行分页  开启分页查询
            String pageNum = searchMap.get("pageNum");
            String pageSize = searchMap.get("pageSize");
            if (StringUtils.isEmpty(pageNum)){
                pageNum = "1";
            }
            if (StringUtils.isEmpty(pageSize)){
                pageSize = "30";
            }
            /**
             * 设置分页
             * 第一个参数：当前页 ，是从 0 开始
             * 第二个参数：每页显示多少条
             */
            nativeSearchQueryBuilder.withPageable(PageRequest.of(Integer.parseInt(pageNum)-1,Integer.parseInt(pageSize)));

            /**
             * 根据价格 进行排序查询
             * 进行排序
             */
            if (StringUtils.isNotEmpty(searchMap.get("sortField")) && StringUtils.isNotEmpty(searchMap.get("sortRule"))){
                if ("ASC".equals(searchMap.get("sortRule"))){
                    //升序
                    nativeSearchQueryBuilder.withSort(SortBuilders.fieldSort(searchMap.get("sortField")).order(SortOrder.ASC));
                }else {
                    //降序
                    nativeSearchQueryBuilder.withSort(SortBuilders.fieldSort(searchMap.get("sortField")).order(SortOrder.DESC));
                }
            }

            //设置高亮区域以及高亮样式
            HighlightBuilder.Field field = new HighlightBuilder.Field("name")  //高亮域
                    .preTags("<span style='color:red'>")  //高亮的前缀标签
                    .postTags("</span>");  //高亮的后缀标签
            nativeSearchQueryBuilder.withHighlightFields(field);

            //开启查询
            /**
             * 第一个参数：条件构建对象
             * 第二个参数：查询操作实体类
             * 第三个参数：查询结果操作对象
             */
            AggregatedPage<SkuInfo> resultInfo = elasticsearchTemplate.queryForPage(nativeSearchQueryBuilder.build(), SkuInfo.class, new SearchResultMapper() {
                @Override
                public <T> AggregatedPage<T> mapResults(SearchResponse searchResponse, Class<T> aClass, Pageable pageable) {

                    List<T> list = new ArrayList<>();
                    //获取查询结果的命中结果
                    SearchHits hits = searchResponse.getHits();
                    for (SearchHit hit : hits) {
                        //将查询的结果转换成 skuInfo 格式
                        SkuInfo skuInfo = JSON.parseObject(hit.getSourceAsString(), SkuInfo.class);
                        //对 高亮的部分 进行替换
                        Map<String, HighlightField> highlightFields = hit.getHighlightFields();
                        if (highlightFields != null && highlightFields.size() >0){
                            //替换数据
                            skuInfo.setName(highlightFields.get("name").getFragments()[0].toString());
                        }
                        list.add((T) skuInfo);
                    }

                    return new AggregatedPageImpl<T>(list,pageable,hits.getTotalHits(),searchResponse.getAggregations());
                }
            });
            //总条数
            resultMap.put("total",resultInfo.getTotalElements());
            //总页数
            resultMap.put("totalPages",resultInfo.getTotalPages());
            //查询结果集合
            resultMap.put("rows",resultInfo.getContent());
            //获取 分组聚合查询后的结果，并将其封装到list中，返回给客户端
            StringTerms brandTerms = (StringTerms) resultInfo.getAggregation(skuBrand);
            /**
             * 流运算  对结果进行遍历，并封装到List中，比 for 循环效率要高
             */
            List<StringTerms.Bucket> buckets = brandTerms.getBuckets();
            Stream<StringTerms.Bucket> stream = buckets.stream();
            Stream<String> stringStream = stream.map(bucket -> bucket.getKeyAsString());
            List<String> brandList = stringStream.collect(Collectors.toList());
//            List<String> brandList = brandTerms.getBuckets().stream().map(bucket -> bucket.getKeyAsString()).collect(Collectors.toList());
            resultMap.put("brandList",brandList);

            //对 规格 信息 分组后，进行封装返回
            StringTerms specTerms = (StringTerms) resultInfo.getAggregation(skuSpec);
            List<String> specList = specTerms.getBuckets().stream().map(bucket -> bucket.getKeyAsString()).collect(Collectors.toList());
            resultMap.put("specList",this.formartSpec(specList));

            //返回当前 是 第几页
            resultMap.put("pageNum",pageNum);

            return resultMap;
        }

        return null;
    }

    /**
     * 原始数据：
     *             "{'颜色': '蓝色', '版本': '6GB+128GB'}",
     *             "{'颜色': '黑色', '版本': '6GB+128GB'}",
     *             "{'颜色': '黑色', '版本': '4GB+64GB'}",
     *             "{'颜色': '蓝色', '版本': '4GB+64GB'}",
     *             "{'颜色': '蓝色', '版本': '6GB+64GB'}",
     *             "{'颜色': '黑色', '版本': '6GB+64GB'}",
     *             "{'颜色': '黑色'}",
     *             "{'颜色': '蓝色'}",
     *             "{'颜色': '金色', '版本': '4GB+64GB'}",
     *             "{'颜色': '粉色', '版本': '6GB+128GB'}"
     *
     * 转换后的数据：
     *              "颜色":["黑色","蓝色"]
     *              "版本":["4GB+64GB","6GB+128GB"]
     * @param specList
     * @return
     */
    public Map<String, Set<String>> formartSpec(List<String> specList){
        Map<String,Set<String>> resultMap = new HashMap<>();
        if (specList != null && specList.size() != 0){
            for (String specString : specList) {
                //将 specString 转换成map 格式
                Map<String,String> specMap = JSON.parseObject(specString, Map.class);
                for (String specKey : specMap.keySet()) {
                    Set<String> specSet = resultMap.get(specKey);
                    if (specSet == null){
                        specSet = new HashSet<String>();
                    }
                    specSet.add(specMap.get(specKey));
                    resultMap.put(specKey,specSet);
                }
            }
        }

        return resultMap;
    }
}
